/*
TASK:sum
LANG:C++
*/

#include<iostream>

using namespace std;

int main() {
    int N,count=0,old_i=1;
    long int suma;
    cin >> N;
    for (int i=1;i<=N/2+1;i++) {
        suma=0;
        for(int j=i;j<N&&suma<N;j++) {
                suma+=j;
                if(suma==N){count++;cout<<i<<' '<<j<<endl;}
        }
    }
    cout<<count;
    return 0;
}
